#3 To freshen up Shane McMahon's character
Much like the rest of his family, Shane McMahon is a natural heel and you have to look at WWE Network clips from the Attitude Era to know exactly what I mean. As great as he's been as a babyface since his return to action, I daresay Shane McMahon is a much better heel than a babyface.
And because he's played the same part for so many years now, maybe it does make sense for Shane McMahon to refresh his character. Of course, this also serves a secondary purpose, to have The Miz get over as a babyface, for the clash at WrestleMania.
If you really think about it, Shane McMahon will be a much better opponent for babyfaces like Kofi Kingston and Mustafa Ali going forward, as opposed to taking on the heels as he has been in this run. Moreover, it also ensures synergy with his father and his sister.
Here comes the money!